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3 years ago

Please help giving 20 points !!! help me out boys asap

Chemistry

1 answer:

pshichka [43]3 years ago

7 0

Not too sure about the first two but that last are solid and then liquid hope this helps!

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When 136g of glycine are dissolved in of a certain mystery liquid , the freezing point of the solution is lower than the freezin

loris [4]

The given question is incomplete. The complete question is:

When 136 g of glycine are dissolved in 950 g of a certain mystery liquid X, the freezing point of the solution is 8.2C lower than the freezing point of pure X. On the other hand, when 136 g of sodium chloride are dissolved in the same mass of X, the freezing point of the solution is 20.0C lower than the freezing point of pure X. Calculate the van't Hoff factor for sodium chloride in X.

Answer: The vant hoff factor for sodium chloride in X is 1.9

Explanation:

Depression in freezing point is given by:

$\Delta T_f=i\times K_f\times m$

$\Delta T_f=T_f^0-T_f=8.2^0C$ = Depression in freezing point

$K_f$ = freezing point constant

i = vant hoff factor = 1 ( for non electrolyte)

m= molality = $\frac{136g\times 1000}{950g\times 75.07g/mol}=1.9$

$8.2^0C=1\times K_f\times 1.9$

$K_f=4.32^0C/m$

Now Depression in freezing point for sodium chloride is given by:

$\Delta T_f=i\times K_f\times m$

$\Delta T_f=20.0^0C$ = Depression in freezing point

$K_f$ = freezing point constant

m= molality = $\frac{136g\times 1000}{950g\times 58.5g/mol}=2.45$

$20.0^0C=i\times 4.32^0C\times 2.45$

$i=1.9$

Thus vant hoff factor for sodium chloride in X is 1.9

3 0

3 years ago

When a solid changes to gas, what is it called??

Kay [80]

When solid changes it's phase to gas without forming liquid, process is called sublimation.

8 0

3 years ago

Can someone help me out with this?

ycow [4]

Answer:

2.8 * 10^(-6) / 1.4 * 10^(-2)=

2* 10^(-8)

4 0

4 years ago

For the following reaction, calculate how many moles of NO2 forms when 0.356 moles of the reactant completely reacts.

Nesterboy [21]

Answer:

0.712 mol of NO₂ are formed .

Explanation:

For the reaction , given in the question ,

2 N₂O₅ ( g ) → 4 NO₂ ( g ) + O₂ ( g )

From the above balanced reaction ,

2 mol of N₂O₅ reacts to give 4 mol of NO₂

Applying unitary method ,

1 mol of N₂O₅ reacts to give 4 / 2 mol of NO₂

From the question , 0.356 mol of N₂O₅ are reacted ,

<u>now, using the above equation , to calculate the moles of the NO₂ , as follow -</u>

Since ,

1 mol of N₂O₅ reacts to give 4 / 2 mol of NO₂

0.356 mol of N₂O₅ reacts to give 4 / 2 * 0.356 mol of NO₂

Calculating ,

0.712 mol of NO₂ are formed .

7 0

3 years ago

What occurs during a slump?

abruzzese [7]

Answer:

A slump is a form of mass wasting that occurs when a coherent mass of loosely consolidated materials or a rock layer moves a short distance down a slope.[1] Movement is characterized by sliding along a concave-upward or planar surface. Causes of slumping include earthquake shocks, thorough wetting, freezing and thawing, undercutting, and loading of a slope.

3 0

2 years ago